This paper discusses a statistical approach to the analysis of power consumption in Class 8 Sleeper Trucks. We will also make recommendations for the electrical design of Class 8 truck.The paper discusses past electrical devices, why device use has increased, and how electrical system design has changed to keep up with truck evolution.We will analyze the electrical loads on the vehicle. This will include a list of cab and sleeper loads common to heavy trucks, current draws, and the advantages this analysis will give to the electrical designers. The analysis also provides peak and average electrical consumption for typical trucks, which helps in optimizing the associated electrical design of a truck power system.Six Sigma is used to analyze the electrical load data. Six Sigma is a systematic, data driven approach to statistically describe a process. Our process of designing an electrical system will greatly benefit from the use of this tool.The paper concludes with summary and recommended practices for an electrical design engineers to improve their system design and to ensure their confidence in an electrical system that will perform to the expectations of their customers.